This invention relates in general to firearms and deals more particularly with a shotgun and other firearm having interchangeable barrels and a telescopic sight for use with at least one of the barrels. A shotgun of the type with which the present invention is concerned is used and has a barrel for firing a slug and a telescopic sight for use with the slug barrel. The gun may also be provided other separate barrels particularly adapted for other types of shooting, such as trap shooting, skeet shooting and grouse hunting. As is customary, the telescopic sight used with the slug barrel is mounted on the receiver and is removed from the gun when the gun is used for another type of shooting. After a barrel change has been made, the telescopic sight must be "sighted-in" to assure accuracy; a time consuming task.
Accordingly, it is the general aim of the present invention to provide a firearm having a removable barrel and a telescopic sight and wherein is unnecessary to "sight-in" the telescopic sight after a barrel change.